Low emission wood burning stove

ABSTRACT

A wood burning stove is configured to produce low emissions and provide high efficiency. The stove includes a housing, a firebox disposed in the housing, a first air flow channel, a secondary air flow channel, and a lower primary air conduit. The secondary air flow channel includes a plurality of secondary air apertures configured to supply secondary air to a combustible gas emitted by a fire. The lower primary air conduit includes a plurality of conduit apertures configured to supply a second primary air flow into the firebox. Also disclosed are methods of operating such a stove.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority to, and any other benefit of,U.S. Provisional Patent Application No. 63/304,199, filed Jan. 28, 2022,the entire disclosure of which is incorporated herein by reference inits entirety.

TECHNICAL FIELD

The present application relates generally to wood burning stoves and,more particularly, to wood burning stoves having increased efficiencyand reduced emissions.

BACKGROUND OF THE INVENTION

Wood burning stoves have been used for hundreds of years to heat homesand other structures or locations. Wood burning stoves have becomecommonplace in buildings for both residential and commercialapplications, particularly where a fireplace is not feasible or desired,for providing heat, decorative purposes, and/or value enhancement. Incertain situations, wood burning stoves may be inserted into fireplaceboxes. Wood burning stoves may also be preferred over fireplaces becausethe wood burning stoves have the capability to heat large spacesefficiently and many wood burning stoves are able to burn for extendedperiods of time without refueling or reloading.

Wood burning stoves are economical sources of heat as they burnrenewable fuel sources such as wood for heat. However, like other heatsources that use combustion, wood burning stoves produce particulateemissions and wood burning stoves may not produce heat as efficiently asother sources of heat production. Accordingly, there is a need forhigher efficiency wood burning stoves with reduced particulateemissions.

SUMMARY

In one embodiment, a lower primary air conduit for use in a wood burningstove includes a body, an intake, and a plurality of conduit apertures.The lower primary air conduit may deliver a flow of air for primarycombustion of a fuel in a firebox of a wood burning stove.

In another embodiment, a wood burning stove includes a housing and afirebox. The stove also includes a primary air flow channel configuredto provide a first flow of primary air into the firebox. The stove alsoincludes a secondary air flow channel configured to provide secondaryair into the firebox. The stove further includes a lower primary airconduit configured to provide a second flow of primary air into thefirebox.

In another embodiment, a method for providing heat from a wood burningstove is disclosed. The method includes the steps of providing fuel intoa firebox of the wood burning stove, igniting the fuel in the firebox,providing a first primary air flow into the firebox from a first airflow channel, providing a secondary air flow into the firebox from atleast one secondary air tube, providing a second primary air flow intothe firebox from a lower primary air conduit, providing a flow of airinto a shroud of the stove, and moving heated air out of side vents ofthe shroud.

A further understanding of the nature and advantages of the presentinvention are set forth in the following description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify various aspects of embodiments of the presentdisclosure, a more particular description of the certain embodimentswill be made by reference to various aspects of the appended drawings.It is appreciated that these drawings depict only typical embodiments ofthe present disclosure and are therefore not to be considered limitingof the scope of the disclosure. Moreover, while the figures can be drawnto scale for some embodiments, the figures are not necessarily drawn toscale for all embodiments. Embodiments and other features and advantagesof the present disclosure will be described and explained withadditional specificity and detail through the use of the accompanyingdrawings in which:

FIG. 1 illustrates an elevated side perspective view of a wood burningstove, according to an exemplary embodiment of the present disclosure;

FIG. 2 illustrates a front view of the wood burning stove of FIG. 1 ;

FIG. 3 illustrates a rear view of the wood burning stove of FIG. 1 ;

FIG. 4 illustrates a side view of the wood burning stove of FIG. 1 ;

FIG. 5 illustrates a top view of the wood burning stove of FIG. 1 ;

FIG. 6 illustrates an elevated side perspective view of the wood burningstove of FIG. 1 with the door removed;

FIGS. 7 and 8 illustrate elevated side perspective views of the woodburning stove of FIG. 1 with the door, upper housing, and upper air flowpaths removed;

FIG. 9 illustrates an elevated side perspective view of the wood burningstove of FIG. 1 with the door, upper flow path, firebricks, and top,front, and sides of the housing removed;

FIG. 10 illustrates an elevated side perspective view of the woodburning stove of FIG. 1 with the door, upper flow path, and top, front,and sides of the housing removed;

FIG. 11 illustrates an illustrated elevated side perspective view offirebricks in a firebox, according to an exemplary embodiment of thepresent disclosure;

FIG. 12 illustrates a cross-sectional side view of the wood burningstove of FIG. 1 ;

FIGS. 13 and 14 illustrate exploded elevated side perspective views of awood burning stove, according to an exemplary embodiment of the presentdisclosure;

FIG. 15 illustrates an elevated side perspective view of an ash bin of awood stove, according to an exemplary embodiment of the presentdisclosure;

FIG. 16 illustrates an elevated side perspective view of a door of awood stove, according to an exemplary embodiment of the presentdisclosure;

FIGS. 17A and 17B illustrated side perspective views of an ash plug of awood stove, according to an exemplary embodiment of the presentdisclosure;

FIG. 18 illustrates an elevated side perspective view of a secondary airflow frame of a wood burning stove, according to an exemplary embodimentof the present disclosure;

FIGS. 19A and 19B illustrate side perspective views of a secondary airtube of a wood burning stove, according to an exemplary embodiment ofthe present disclosure;

FIG. 20 illustrates a side perspective view of another secondary airtube of a wood burning stove, according to an exemplary embodiment ofthe present disclosure;

FIGS. 21A-21D illustrate views of a lower primary air conduit of a woodburning stove, according to an exemplary embodiment of the presentdisclosure;

FIG. 22 illustrates a cross-sectional schematic view of air flows in awood burning stove, according to an exemplary embodiment of the presentdisclosure;

FIG. 23 illustrates an elevated side perspective view of a damper for awood burning stove, according to an exemplary embodiment of the presentdisclosure;

FIG. 24 illustrates an elevated side perspective view of a shroud for awood burning stove, according to an exemplary embodiment of the presentdisclosure;

FIG. 25 illustrates an elevated side perspective view of a blower for awood burning stove, according to an exemplary embodiment of the presentdisclosure;

FIGS. 26-29 illustrate schematic views of a wood burning stove connectedto a chimney, according to an exemplary embodiment of the presentdisclosure;

FIG. 30 illustrates steps of a method for providing heat from a woodburning stove, according to an exemplary embodiment of the presentdisclosure; and

FIG. 31 illustrates an elevated side perspective view of another woodburning stove, according to an exemplary embodiment of the presentdisclosure.

DETAILED DESCRIPTION

The following description refers to the accompanying drawings, whichillustrate specific embodiments of the present disclosure. Otherembodiments having different structures and operation do not depart fromthe scope of the present disclosure.

Referring to FIGS. 1-14 , a wood burning stove 10 is depicted accordingto one embodiment. The stove 10 includes a housing 12. The housing 12may be any suitable shape or size. In the illustrated embodiment, thehousing 12 is generally cubical and includes a front side 14, a rearside 16, a first or left side 18, a second or right side 20, a top 22,and a base 24, which may be used to allow the stove 10 to stand on asurface.

The stove 10 includes a firebox 26 disposed within the housing 12. Thefirebox 26 may include a front wall 28, a rear wall 30, a first or leftside wall 32, a second or right side wall 34, a ceiling 36, and a floor38. The floor 38 may be sized, shaped, or otherwise configured toreceive a solid fuel source, such as wood, and the firebox 26 may besized, shaped, or otherwise configured to permit the fuel to burn. Thefloor 38 may also include a floor aperture 40 (FIG. 9 ) disposedgenerally in the middle of the floor 38 which may allow ash or otherdebris to be removed from the firebox 26, as described below. In theillustrated embodiment, the firebox 26 is generally box shaped. However,the firebox 26 may be any suitable shape, size, or configuration. Forexample, the firebox 26 may be curved, rounded, triangular, spherical,or any other suitable shape.

As shown in FIGS. 6-8 and 10-11 , the firebox 26 may also include one ormore firebricks 42 disposed on one or more of the floor 38, the frontwall 28, the rear wall 30, the left side wall 32, and the right sidewall 34 to refract or maintain heat in the firebox 26, such as when afuel is burned in the firebox 26. The firebricks 42 may be thermalrefractory bricks used in lining fireboxes, stoves, or fireplaces andmay be made of any suitable material, such as fire clay, and may be ableto withstand high temperatures, such as temperatures in excess of 2000°F. The firebricks 42 may be positioned within the firebox 26 to increasethe thermal retention of the firebox 26 and may be positioned so as notto obstruct the floor aperture 40 or an opening into the firebox 26, asdescribed below. As shown in the illustrated embodiment, the firebricks42 may be generally rectangular in shape. However, the firebricks 42 mayany suitable size, shape, or configuration. For example, the firebricks42 may be in the shape of triangles, pentagons, hexagons, or any othersuitable shape and the sides and edges may be tapered, rounded,chamfered, or any other suitable shape or configuration. In theillustrated embodiment, the stove 10 includes firebricks 42 of fivedifferent sizes and shapes (see A, B, C, D, and E in FIG. 11 ). However,the stove 10 may have any suitable combination of firebricks 42. 44

While the firebox 26 is described as including one or more firebricks 42disposed on one or more of the floor 38, the front wall 28, the rearwall 30, the left side wall 32, and the right side wall 34, otherembodiments are contemplated. For example, one or more of the floor 38,the front wall 28, the rear wall 30, the left side wall 32, and theright side wall 34 may comprise or be composed of one or more firebricks42.

As shown in FIGS. 13-14 , the stove 10 may also include one or moreceramic fiberboards 44 disposed in an upper portion of the firebox 26opposite the floor 38. The one or more ceramic fiberboards 44 may bedisposed on the underside or below the ceiling 36 of the firebox 26 andconfigured to retain or refract heat within the firebox 26. The one ormore ceramic fiberboards 44 may be disposed next to each other along thesurface of the ceiling 36 of the firebox 26 and substantially cover thesurface of ceiling 36. The ceramic fiberboards 44 may have a similarcomposition to the one or more firebricks 42 and may be made of anysuitable material, such as fire clay, and may and may be able towithstand high temperatures, such as temperatures in excess of 2000° F.

As shown in FIGS. 14 , the stove 10 may optionally include a ceramicblanket 46 disposed in an upper portion of the firebox 26 opposite thefloor 38. The ceramic blanket 46 may be disposed on the underside of theceiling 36 of the firebox 26 above the one or more ceramic fiberboards44 or may be disposed on the underside or below the one or more ceramicfiberboards 44. The ceramic blanket 46 may be disposed along the surfaceof the ceiling 36 or the surfaces of the one or more ceramic fiberboards44 and may substantially cover the surface of the ceiling 36 and or theone or more ceramic fiberboards 44. The ceramic blanket 46 may have asimilar composition to the one or more firebricks 42 and/or the one ormore ceramic fiberboards 44 and may be made of any suitable material,such as fire clay, and may and may be able to withstand hightemperatures, such as temperatures in excess of 2000° F. In otherembodiments, the ceramic blanket 46 may define the ceiling 36 of thefirebox 26.

As shown in FIGS. 6-7 , the stove 10 may include a housing opening 48 inthe front side 14 of the housing 12 and extending into the firebox 26.The housing opening 48 may be sized, shaped, and otherwise configuredsuch that a user may load a fuel source, such as wood, into the firebox26 through the housing opening 48.

As shown in FIGS. 1-4 and 12-16 , the housing 12 may also include a door50 which may be moveable between an open and closed position which mayopen and close the housing opening 48. The door 50 may be sized, shaped,and configured such that the door 50 substantially seals the firebox 26and retains heat within the firebox 26 when the door is in the closedposition. In the illustrated embodiment, the door 50 is pivotablyattached to the front side 14 of the housing 12 on one side of thehousing opening 48 such that the door 50 may be pivoted between the openand closed positions. For example, the door 50 may be pivotably attachedto the front side of the housing 12 with a hinge such that it ispivotable between open and closed positions. However, the door 50 may beaffixed to the housing 12 and moveable between the open and closedpositions in any suitable manner. For example, the door 50 may beslidably affixed to the front side 14 of the housing 12 such that thedoor 50 may be slid along the front side 14 to open and close thehousing opening 48. Optionally, the door 50 may have a glass portion orwindow 52 such that a user may at least partially view the contents ofthe firebox 26 when the door 50 is in the closed position.

The door 50 may include a lever 54 which may be used to secure the door50 to the housing 12 when the door 50 is in the closed position. Thelever 54 may include a flange 56 which extends inwardly into the housing12 from the door 50 when the door 50 is in the closed position. Theflange 56 may be rotated by rotational movement of the lever 54 and maybe secured in or by a hook 60 extending inwardly from the front side 14of the housing 12 into the firebox 26, such as by a clockwise rotationalmovement of the lever 54. The flange 56 may be released from the hook 60via opposite rotational movement of the lever 54, such as acounterclockwise rotational movement of the lever 54, such that the door50 may be freely moveable between the open and closed positions.Optionally, the lever 54 may also include a handle 58 at an end of thelever 54 which may be comfortably and safely grasped by a user tomanipulate the position of the lever 54 and the door 50. The handle 58may have any suitable shape, size, or configuration such that a user maycomfortably and safely grasp the handle 58 during operation of the stove10. For example, the handle 58 may be designed, shaped, or otherwiseconfigured such that the handle 58 is at least relatively cool to thetouch when a fuel source is burned in the firebox 26.

As shown in FIGS. 12-14 , the housing 12 may have a lower portion 25disposed below the firebox 26 which includes an ash bin 62 disposedsubstantially below the floor aperture 40 of the firebox 26. The ash bin62 may be configured to receive ashes or other debris from the firebox26 through the floor aperture 40 and allow a user to remove the ash orother debris from the stove 10. In the illustrated embodiment, the ashbin 62 is substantially rectangular. However, it will be appreciatedthat the ash bin 62 may have any suitable shape. For example, the ashbin 62 may be triangular, rounded, or any other suitable shape. The ashbin 62 may be slidably removed from the housing 12 such that a user mayremove the ash bin 62 from the housing 12 to dispose of the contents ofthe ash bin 62.

Further, as shown in FIGS. 12-14 and 17A-17B, the stove 10 may alsoinclude an ash plug 64 which is sized and shaped to be at leastpartially disposed in the floor aperture 40 and to prevent fuel fromfalling from the firebox 26 into the ash bin 62 when the ash plug 64 isin place in the floor aperture 40. The ash plug 64 may be sized, shaped,or otherwise configured to prevent ash or other debris from fallingthrough the floor aperture 40 and to substantially prevent the flow ofair through the floor aperture 40 when the fuel is combusted in thefirebox 26. The ash plug 64 may have a plug portion 66 sized and shapedto fit in the floor aperture 40 and a hook portion 68 configured to begrasped by a user. The ash plug 64 may be sized, shaped, and configuredsuch that a user may grasp the hook portion 68 when the fuel is notburning in the firebox 26, remove the ash plug 64 from the flooraperture 40, sweep the ashes through the floor aperture 40 and into theash bin 62, empty the ash bin 62, such as in a suitable container, andreplace the plug portion 66 in the floor aperture 40.

In one embodiment, as best shown in FIGS. 17A-17B, the ash plug 64 mayalso include a platform 70 between the plug portion 66 and the hookportion 68 which extends outwardly and defines a substantially flatsurface. The ash plug 64 may be sized, shaped, or otherwise configuredsuch that the platform 70 is substantially the same height as thefirebricks 42 disposed on the floor 38 of the firebox 26 when the ashplug 64 is disposed in the floor aperture 40 and substantially coversthe portion of the floor 38 the firebricks 42 do not cover, therebydefining a substantially continuous and substantially level surface fora fuel to be placed in the firebox 26. Further, the platform 70 mayinclude one or more supports 72 which extend downwardly from theplatform 70 and are configured to keep the platform 70 at substantiallythe same height as the firebricks 42 disposed on the floor 38 of thefirebox 26 when the plug portion 66 is disposed in the floor aperture40. The supports 72 may also be sized, shaped, or otherwise configuredsuch that the ash plug 64 may adequately support fuel placed in thefirebox 26 for combustion.

As shown in FIGS. 3, 4, 8, 12, and 22 , the housing 12 may include afresh air intake or rear air opening 74 disposed in a lower portion ofthe rear side 16 of the housing 12. The rear air opening 74 may bedisposed below the firebox 26 and be configured to deliver a flow ofprimary air into the lower portion 25 housing 12 from outside the stove10. The rear air opening 74 may be sized, shaped, or otherwiseconfigured to supply a desired amount of air from outside the stove 10into the firebox 26 as detailed below. Optionally, the rear air opening74 may be combined with or connected to a pipe or other suitable conduitto receive air from a remote location, such as from outside the room orbuilding in which the stove 10 is located (FIG. 29 ).

Referring to FIGS. 12 and 22 , the housing 12 may further include afirst air flow channel 76 configured to deliver a first flow of primaryair into the firebox 26. As used herein, the term “primary air” refersto air supplied for a first or primary combustion of a fuel source, suchas wood, in the firebox 26 which produces or emits smoke which mayinclude a combustible gas. The term “secondary air” refers to airsupplied for a secondary combustion in the firebox 26 which is theburning of combustible gas emitted by the first or primary combustion.The first air flow channel 76 may be positioned, oriented, or otherwiseconfigured to increase heat output of the stove 10, to increase theefficiency of the stove 10, and/or to reduce the particulate emissionsfrom the stove 10.

The first air flow channel 76 may extend from the lower portion 25 ofthe housing 12 to an upper portion of the firebox 26 to supply primaryair to the firebox 26. The first air flow channel 76 may have an inlet78 disposed substantially above the rear air opening 74 and configuredto receive air from the rear air opening 74 and/or the lower portion 25of the housing 12. The inlet 78 may be located in a rear portion of thehousing 12 between the firebox 26 and the rear side 16 of the housing 12at the same or similar height to the floor 38 of the firebox 26. Theinlet 78 may have any suitable size, shape, or configuration suitable toreceive a flow of air from the rear air opening 74 and/or the lowerportion 25 of the housing 12 to deliver to the firebox 26, as describedbelow. For example, the inlet 78 of the first air flow channel 76 may besubstantially rectangular. However, the inlet 78 may have any othersuitable configuration. For example, the inlet 78 may be rounded,triangular, elliptical, or any other suitable shape.

The first air flow channel 76 may extend upwardly from the inlet 78through the housing 12 between the rear side 16 of the housing 12 andthe rear wall 30 of the firebox 26 to an upper portion of the housing 12near the top 22 of the housing 12. The first air flow channel 76 maythen divide and extend along the rear wall 30 to the left and right sidewalls 32, 34 along an underside of the top 22 of the housing 12. Thefirst air flow channel 76 may then extend along the top of the housing12 from the rear side 16 of the housing 12 to the front side 14 of thehousing 12 between the top 22 of the housing 12 and the ceiling 36 ofthe firebox 26 along both the left and right side walls 32, 34. The twoportions extending along the left and right side walls 32, 43 may thenconverge along the front side 14 of the housing 12. The first air flowchannel 76 may then extend downwardly along a portion of the front side14 of the housing 12. Optionally, the first air flow channel 76 mayextend at least partially into the door 50. The first air flow channel76 may have an outlet 80 (FIG. 22 ) configured to deliver primary airinto the firebox 26. The outlet 80 may be in be in or extend through thefront wall 28 of the firebox 26 in an upper portion of the firebox 26near the ceiling 36 of the firebox 26. The outlet 80 may be orienteddownwardly at an angle to direct primary air toward a fuel sourcedisposed on the floor 38 of the firebox 26. For example, the outlet 80may be oriented to direct primary air toward the floor aperture 40.

Referring to FIGS. 1-2, 4-8, 22, and 23 , the stove 10 may also includea first or primary damper 82 having a rod portion 84 and a stopperportion 86 configured to permit or control the amount of air flowthrough the first air flow channel 76. The rod portion 84 of the primarydamper 82 may extend through a damper aperture 90 in an upper portion ofthe front side 14 of the housing 12 near the top 22 of the housing 12and into the first air flow channel 76. The rod portion 84 may be sized,shaped, and otherwise configured such that the stopper portion 86 of theprimary damper 82 may be disposed in a rear portion of the first airflow channel 76 (e.g., the portion of the first air flow channel 76between the rear wall 30 of the firebox 26 and the rear side 16 of thehousing 12) and be at least partially moveable between the rear side 16of the housing 12 and an upper portion of the first air flow channel 76(e.g., the portion of the first air flow channel 76 between the rearportion of the first air flow channel 76 and the front side 14 of thehousing 12). The primary damper 82 may be slidable or otherwise moveablethrough the damper aperture 90 (FIG. 2 ) in an upper portion of thefront side 14 of the housing 12 such that the stopper portion 86 of theprimary damper 82 is moveable, slidable, or otherwise positionablebetween a closed, partially opened, and opened configuration. Thestopper portion 86 of the primary damper 82 may be sized, shaped, orotherwise configured such that, in the closed position, the stopperportion 86 may seal or otherwise prevent the flow of air from the rearportion of the first air flow channel 76 to the upper portion of thefirst air flow channel 76. For example, the rod portion 84 of theprimary damper 82 may be pulled or otherwise moved away from the frontside 14 of the housing 12 such that the stopper portion 86 of theprimary damper 82 is moved toward the upper portion of the first airflow channel 76 to restrict or prevent the flow of air from the rearportion of the first air flow channel 76 into the upper portion of thefirst air flow channel 76 and thereby prevent the flow of air throughthe first air flow channel 76 into the firebox 26. Further, in the openposition, the rod portion 84 may be pushed into the housing 12 such thatthe stopper portion 86 is disposed the furthest distance opposite theupper portion of the first air flow channel 76, thereby permitting amaximum amount of air to flow from the rear portion of the first airflow channel 76 into the upper portion of the first air flow channel 76.In the partially open position, the rod portion 84 of the primary damper82 may my slid or otherwise moved such that the stopper portion 86 isbetween the closed position and the open position, thereby permitting adesired amount of airflow between no airflow and the maximum amount ofairflow. The primary damper 82 may be slidable or positionable between ahigh burn position permitting a maximum amount of air to flow throughthe first air flow channel 76, a medium burn position permitting anintermediate amount of air to flow through the first air flow channel76, and a low burn position permitting a low or negligible amount of airto flow through the first air flow channel 76 or prevent the flow of airthrough the first air flow channel.

The stove 10 and/or primary damper 82 may also have any suitablealternative configuration to control the amount of air supplied to thefirebox 26. For example, the primary damper 82 may be positioned in thestove 10 such that the stopper portion 86 of the primary damper 82 isdisposed in the upper portion of the first air flow channel 76 and maybe moved, slid, or otherwise positioned such that the stopper portion 86may close or prevent airflow from the rear portion of the first air flowchannel 76, such as by abutment with an opening of the rear portion ofthe first air flow channel 76. In such embodiment, the primary damper 82may be moved to the closed position by sliding or moving the primarydamper 82 through the damper aperture 90 toward the rear side 16 of thehousing 12 until the stopper portion 86 abuts and/or prevents the flowof air from the rear portion of the first air flow channel 76. Theprimary damper 82 may then be moved to the partially open position bymoving or sliding the stopper portion 86 toward the front side 14 of thehousing 12 to permit some amount of air flow from the rear portion ofthe first air flow channel 76 into the upper portion of the first airflow channel 76. The primary damper 82 may be moved to the open positionby moving or sliding the stopper portion 86 toward the front side 14 ofthe housing 12 to permit a maximum amount of air flow from the rearportion of the first air flow channel 76 into the upper portion of thefirst air flow channel 76.

It will be appreciated that the stove 10 may have other suitablelocations and configurations of the primary damper 82. In anotherembodiment, as shown in FIG. 31 , the primary damper 82 of the stove 10extends into the housing 12 through the right side 20 of the housing 12.In such a configuration, the primary damper 82 may be similarly used topermit or control the amount of air flow through the first air flowchannel 76, as described above. The stove 10 may also have othersuitable primary damper 82 configurations. For example, the primarydamper 82 may extend into the housing 12 through the left side 18 of thehousing, through the rear side 16 of the housing 12, or through the top22 of the housing 12 to similarly to permit or control the amount of airflow through the first air flow channel 76, as described above.

In some embodiments, the primary damper 82 may also include a damperhandle 88 which may be grasped by a user such that the user is notburned or otherwise injured when grasping the damper handle 88 when thefuel is burned in the firebox 26. While the stove 10 is depicted ashaving one damper, the stove 10 may have any suitable number andconfiguration of dampers. For example, the stove 10 may have a damperconfigured to control airflow through each of the air flow channels asdescribed herein.

Referring to FIGS. 7, 8, 12-14, 18-20, and 22 , the stove 10 may alsoinclude a secondary air flow channel 92 (shown in FIGS. 12 and 22 )configured to deliver a flow of secondary air to the firebox 26. Thesecondary air flow channel 92 may include a secondary air flow frame 94with an inlet configured to receive a flow of air into the secondary airflow frame 94. The inlet of the secondary air flow frame 94 may be incommunication with the first air flow channel 76 to receive a flow ofair from the first air flow channel 76. For example, the inlet of thesecondary air flow frame 94 may receive a flow of air from the rearportion of the first air flow channel 76 below the upper portion of thefirst air flow channel 76. The inlet of the secondary air flow frame 94may receive air from the first air flow channel 76 at a location belowthe stopper portion 86 of the primary damper 82 such that the flow ofair from the first air flow channel 76 into the secondary air flow frame94 is not substantially affected by the position of the stopper portion86 of the primary damper 82. The secondary air flow channel 92, andcomponents thereof, may be positioned, oriented, or otherwise configuredto increase heat output of the stove 10, increase the efficiency of thestove 10, and/or to reduce the particular emissions from the stove 10.

The secondary air flow frame 94 may be substantially rectangular andU-shaped with a rear portion which extends from the inlet incommunication with the first air flow channel 76 along the rear wall 30of the firebox 26 toward the left and right side walls 32, 34 of thefirebox 26. The secondary air flow frame 94 may also have leg portionswhich extend from the rear wall 30 of the firebox 26 toward the frontwall 28 along the left and right side walls 32, 34, respectively. Theleg portions may be disposed on and extend along the left and right sidewalls 32, 34 of the firebox 26 or may be inset from the left and rightside walls 32, 34, respectively. The leg portions of the secondary airflow frame 94 may have one or more frame apertures 95 disposed in aninner or medial side of the leg portions to accommodate and/or providesecondary air to secondary air tubes, as described below. The secondaryair flow frame 94 may be sized, shaped, positioned, or otherwiseconfigured such that the leg portions of the secondary air flow frame 94are disposed in an upper portion of the firebox 26. The secondary airflow frame 94 may also include one or more dampers which may regulatethe flow of secondary air through the secondary air flow frame 94.

As shown in FIGS. 7-8, 12-15, 18-20, and 22 , the secondary air flowchannel 92 of the stove 10 may also include or be defined by one or moresecondary air tubes 96 disposed in an upper portion of the firebox 26and configured to deliver a flow of secondary air to the firebox 26. Thesecondary air tubes 96 may be disposed between the frame apertures 95 ofthe secondary air flow frame 94. The secondary air tubes 96 may beconnected to the secondary air flow frame 94 in flow communication toreceive a flow of air from the secondary air flow frame 94. Thesecondary air tubes 96 may be connected to the secondary air flow frame94 such that the secondary air tubes 96 are disposed above the floor 38of the firebox 26 and below the ceiling 36 of the firebox 26, the one ormore ceramic fiberboards 44, and/or the ceramic blanket 46 and may bedisposed substantially parallel to the front wall 28 and the rear wall30. In the illustrated embodiment, the stove 10 includes three secondaryair tubes 96 (a first secondary air tube 96 a, a second secondary airtube 96 b, and a third secondary air tube 96 c). However, it will beappreciated that the stove 10 may include any number of secondary airtubes 96. For example, the stove 10 may have one, two, or four or moresecondary air tubes 96. Further, in the illustrated embodiment, thesecondary air tubes 96 are substantially cylindrical in shape. However,it will be appreciated that the secondary air tubes 96 may have anysuitable shape, size, or configuration. For example, the secondary airtubes 96 may be rectangular in shape or may incorporate any number ofbends along the length of the secondary air tube 96.

Each secondary air tube 96 may include an air intake or entrance 98 ineach end of the secondary air tube 96 configured to receive secondaryair from the frame apertures 95 of secondary air flow frame 94 and oneor more exits or secondary air apertures 100 disposed along the lengthof the secondary air tube 96 and configured to allow the secondary airto exit the secondary air tube 96 and thereby mix with a combustible gasemitted by a fire located in the firebox 26. The secondary air tubes 96may be sized and shaped such that the secondary air tubes 96substantially extend between each corresponding pair of frame apertures95 of the secondary air flow frame 94 and substantially fill or coverthe frame apertures 95 of the secondary air flow frame 94 such that thesecondary air from the secondary air flow frame 94 may flow through theframe apertures 95 into both air intakes 98 of each secondary air tube96.

Each secondary air tube 96 may also include one or more tabs 102disposed at one of the ends of the secondary air tube 96 near the airintake 98. The tab 102 may be positioned on the secondary air tube 96and configured such that the secondary air tube 96 may be affixed to thesecondary air flow frame 94 in the desired position or orientation, suchas detailed below. The tab 102 may be affixed or connected to thesecondary air flow frame 94 by any suitable means. For example, the tab102 may be affixed or connected to the secondary air flow frame 94 bywelding, a fastener, or any other suitable means. Alternatively, inother embodiments, the secondary air tubes 96 may be integral with thesecondary air flow frame 94.

Referring to FIG. 22 , the secondary air flow channel 92 may beconfigured to deliver a flow of secondary air into the firebox 26 to mixwith a combustible gas emitted by a fire located in the firebox 26 andthereby provide a secondary combustion within the firebox 26. The flowof secondary air may enter the lower portion 25 of the housing 12through the rear air opening 74 and then flow upwardly into the firstair flow channel 76 toward the secondary air flow channel 92. Thesecondary air may flow from the first air flow channel 76 into the rearportion of the secondary air flow frame 94 and into the leg portions ofthe secondary air flow frame 94. The secondary air may then flow fromthe leg portions of the secondary air flow frame 94 into the secondaryair tubes 96 through the frame apertures 95 into the air intakes 98 andflow out the secondary air apertures 100 into an upper portion of thefirebox 26.

The secondary air flow frame 94 and the secondary air tubes 96 may bepositioned, oriented, or otherwise configured such that secondary airmay flow through the secondary air flow channel 92 and out of thesecondary air apertures 100 in the desired amount, position, andorientation for secondary combustion in the firebox 26. For example, thesecondary air flow frame 94 and the secondary air tubes 96 may bepositioned, oriented, or otherwise configured to increase heat output ofthe stove 10, increase the efficiency of the stove 10, and/or reduce theparticulate emissions from the stove 10.

The secondary air flow frame 94 may be sized, shaped, positioned, orotherwise configured to provide the desired amount of air flow throughthe secondary air flow channel 92, such as to increase heat output ofthe stove 10, to increase the heating efficiency of the stove 10, and/orto reduce particulate emissions from combustion in the stove 10. In oneembodiment, the secondary air flow frame is tilted or angled upwardlyfrom the connection with the first air flow channel 76 such that theportion of the secondary air flow frame 94 nearer the front wall 28 ofthe firebox 26 is higher (e.g., farther away from the floor 38 of thefirebox 26) than the portion of the secondary air flow frame 94connected to the first air flow channel 76. For example, the secondaryair flow frame 94 may be angled upwardly between about 0° and 20° from ahorizontal plane extending outwardly from the connection of thesecondary air flow frame 94 and the first air flow channel 76, such asbetween about 2° upwardly and about 10° upwardly, such as about 5°upwardly.

The secondary air tubes 96 may be sized, shaped, positioned, orotherwise configured to provide the desired amount and orientation ofair flow from the secondary air flow channel 92. The secondary air tubes96 may include any number and configuration of secondary air apertures100 such that the secondary air flows out of the secondary air apertures100 in the desired amount, position, and orientation. In one embodiment,each of the secondary air tubes 96 includes a plurality of secondary airapertures 100 disposed linearly along a length of the secondary airtubes 96. The secondary air apertures 100 may be evenly spaced along thelength of the secondary air tubes 96 with a center hole distance betweeneach secondary air aperture 100 between about 0.25 inches and about 1.0inch, such as between about 0.35 inches and about 0.75 inches, such ashaving about a 0.5 inch center hole distance between each secondary airaperture 100. In the illustrated embodiment, each secondary air tube 96includes 34 secondary air apertures 100 evenly spaced along a length ofthe secondary air tube 96. However, the secondary air tubes 96 may haveany suitable spacing or configuration of secondary air apertures 100.For example, the secondary air tubes 96 may have an uneven distributionof secondary air apertures 100, such as with the secondary air apertures100 being grouped closer to one or both of the air intakes 98, groupedcloser to a medial portion of the secondary air tube 96, or any othersuitable configuration.

Referring to FIGS. 7, 8, 12-15, 18-20, and 22 , the secondary air tubes96 may be attached to the secondary air flow frame 94 with the tab 102such that the secondary air tube 96 and/or secondary air apertures 100are oriented to provide secondary air into the firebox 26 in the desireddirection or orientation. The tabs 102 of the secondary air tubes 96 maybe affixed to secondary air flow frame 94 at an angle with thehorizontal plane such that the secondary air tubes 96 and/or secondaryair apertures 100 are disposed at an angle in the firebox 26. Forexample, the tabs 102 of the secondary air tube 96 may be attached tothe secondary air flow frame 94 at an upward angle to the horizontalplane between about 0° and about 90°, such as between about 20° and 60°upward relative to the horizontal plane, such as about 35° upwardrelative to the horizontal plane.

The secondary air apertures 100 may be disposed or oriented along thesecondary air tubes 96 relative to the tab 102 such that the secondaryair exits the secondary air apertures 100 in the desired direction ororientation. The secondary air apertures 100 may also be sized, shaped,or otherwise configured such that the desired amount of secondary airflows out of each of the secondary air tubes 96. In the illustratedembodiment, the stove 10 includes three secondary air tubes 96 with afirst secondary air tube 96 a disposed closer to the front wall 28, asecond secondary air tube 96 b disposed between the other two secondaryair tubes 96, and a third secondary air tube 96 c disposed closer to therear wall 30. However, it will be appreciated that the stove 10 mayinclude any number of secondary air tubes 96 in any suitableconfiguration.

As shown in FIGS. 19A and 19B, the secondary air apertures 100 of thefirst secondary air tube 96 a may be sized, spaced, oriented, orotherwise configured to supply a desired amount of secondary air intothe firebox 26. The secondary air apertures 100 of the first secondaryair tube 96 a may be disposed or oriented relative to the tab 102 of thefirst secondary air tube 96 a such that the secondary air apertures 100of the first secondary air tube 96 a deliver secondary air into thefirebox 26 at the angle desired for secondary combustion. For example,the secondary air apertures 100 of the first secondary air tube 96 a maybe disposed opposite the tab 102 at an angle (clockwise around thecircumference of the tube) between about 90° and about 210° relative tothe orientation of the tab 102 of the first secondary air tube 96 a,such as between about 120° and about 160° relative to the orientation ofthe tab 102, such as about 145° relative to the orientation of the tab102. The secondary air apertures 100 of the first secondary air tube 96a may also be sized to deliver secondary air into the firebox 26 at theamount desired for secondary combustion. For example, the secondary airapertures 100 of the first secondary air tube 96 a may have a diameterbetween about 0.10 inches and about 0.25 inches, such as between about0.15 inches and about 0.20 inches, such as about 0.195 inches.

As shown in FIG. 20 , the secondary air apertures 100 of the secondsecondary air tube 96 b may be sized, spaced, oriented, or otherwiseconfigured to supply a desired amount of secondary air into the firebox26. The secondary air apertures 100 of the second secondary air tube 96b may be disposed or oriented relative to the tab 102 of the secondsecondary air tube 96 b such that the secondary air apertures 100 of thesecond secondary air tube 96 b deliver secondary air into the firebox 26at the angle desired for secondary combustion. For example, thesecondary air apertures 100 of the second secondary air tube 96 b may bedisposed in line with the tab 102 at an angle (clockwise around thecircumference of the tube) between about 0° and about 20° relative tothe orientation of the tab 102 of the second secondary air tube 96 b,such as between about 2° and about 10° relative to the orientation ofthe tab 102, such as about 5° relative to the orientation of the tab102. The secondary air apertures 100 of the second secondary air tube 96b may also be sized to deliver secondary air into the firebox 26 at theamount desired for secondary combustion. For example, the secondary airapertures 100 of the second secondary air tube 96 b may have a diameterbetween about 0.10 inches and about 0.25 inches, such as between about0.15 inches and about 0.20 inches, such as about 0.18 inches.

The secondary air apertures 100 of the third secondary air tube 96 c mayalso be sized, spaced, oriented, or otherwise configured to supply adesired amount of secondary air into the firebox 26. The secondary airapertures 100 of the third secondary air tube 96 c may be disposed ororiented relative to the tab 102 of the third secondary air tube 96 csuch that the secondary air apertures 100 of the third secondary airtube 96 c deliver secondary air into the firebox 26 at the angle desiredfor secondary combustion. For example, the secondary air apertures 100of the third secondary air tube 96 c may be disposed in line the tab 102at an angle (clockwise around the circumference of the tube) betweenabout 0° and about 20° relative to the orientation of the tab 102 of thethird secondary air tube 96 c, such as between about 2° and about 10°relative to the orientation of the tab 102, such as about 5° relative tothe orientation of the tab 102. The secondary air apertures 100 of thesecond secondary air tube 96 b may also be sized to deliver secondaryair into the firebox 26 at the amount desired for secondary combustion.For example, the secondary air apertures 100 of the third secondary airtube 96 c may have a diameter between about 0.10 inches and about 0.25inches, such as between about 0.11 inches and 0.20 inches, such as about0.15 inches.

While the secondary air tubes 96 are described as having 34 secondaryair apertures 100 evenly spaced along the secondary air tube 96, thesecondary air tubes 96 may have any suitable configuration of secondaryair apertures 100. For example, the secondary air tubes 96 may have anynumber of secondary air apertures 100 (such as between 1 and 33secondary air apertures 100 or 35 or more secondary air apertures 100),the secondary air apertures 100 may not be linearly disposed along thesecondary air tube 96 (such as being oriented in different radialdirections along the length of the secondary air tubes 96), thesecondary air apertures 100 may not be evenly distributed along thesecondary air tubes 96 (such as unevenly distributed or grouped closertogether along medial portions of the secondary air tubes 96), and/orthe secondary air apertures 100 may have different shapes. Further, eachsecondary air tube 96 may have a different number and/or configurationof secondary air apertures 100.

As shown in FIGS. 6, 7, 9, 10, 12-14, 21A-21D, and 22 , the stove 10 mayalso include a lower primary air conduit 104 which may supply a thirdflow of air or a second flow of primary air into the firebox 26. Thelower primary air conduit 104 may be generally L-shaped and extend fromthe lower portion 25 of the housing 12 into the firebox 26 through thefloor 38 of the firebox 26 near the front wall 28. The lower primary airconduit 104 may have a body with an intake portion or base portion 105and an outlet or neck portion 107 extending upwardly from the baseportion 105. The lower primary air conduit 104 may include a lowerintake 106 disposed in a bottom of the base portion 105 configured toreceive air from the lower portion 25 of the housing 12. For example, abottom of the base portion 105 may be open and define the lower intake106 such that the lower intake 106 may receive air from the lowerportion 25. The neck portion 107 may be substantially hollow with anopening or passage connecting an inner portion of the neck portion 107with the lower intake 106 such that air from the lower portion 25 flowsinto an inside portion of the neck portion 107. The neck portion 107 mayinclude one or more conduit apertures 108 disposed in one or more facesof the neck portion 107. The conduit apertures 108 may be configured tosupply air from the lower intake 106 into the firebox 26. For example,the conduit apertures 108 may be disposed in a rear wall or face 107 aof the neck portion 107 to supply air from the lower intake toward therear wall 30 of the firebox 26. The base portion 105 may extendrearwardly from the rear face 107 a of the neck portion 107 such that aportion of the base portion 105 may be disposed rearwardly of theconduit apertures 108 in the neck portion 107.

The lower primary air conduit 104 may have any suitable size, shape, orconfiguration to provide a desired flow of primary air into the firebox26. For example, the lower primary air conduit 104 may be sized, shaped,or otherwise configured to increase heat output of the stove 10, toincrease the heating efficiency of the stove 10, and/or to reduceparticulate emissions from combustion in the stove 10. In theillustrated embodiment, the base portion 105 of the lower primary airconduit 104 is substantially box-shaped with an open bottom and the neckportion 107 is substantially a half cylinder with conduit apertures 108disposed in the curved rear face 107 a of the neck portion 107. The neckportion 107 also includes a front face 107 b which may be substantiallyplanar. The neck portion 107 may be disposed above a front portion ofthe base portion 105 of the lower primary air conduit 104 such that theplanar front face 107 b of the neck portion 107 is substantiallycontinuous with a front wall or face of the base portion 105. The lowerprimary air conduit 104 may be disposed in the front of the firebox 26such that the front face of the base portion 105 and the front face 107b of the neck portion 107 are substantially aligned with the front wall28 of the firebox 26. One or more conduit apertures 108 may be disposedin the rear wall of the neck portion 107 to provide a flow of air fromthe lower portion 25 toward the rear wall 30 of the firebox 26.

The lower primary air conduit 104 may extend to any suitable height inthe firebox 26 to provide the desired flow of primary air. For example,the lower primary air conduit 104 may extend to a height between about2.0 inches and about 3.6 inches above the floor 38 of the firebox 26,such as between about 2.5 inches and about 3.3 inches above the floor 38of the firebox 26, such as about 2.8 inches above the floor 38 of thefirebox 26. In one embodiment, the one or more conduit apertures 108 aredisposed and configured to direct air from the lower primary air conduit104 away from the front wall 28 of the firebox 26 and into a lower andcentral portion of the firebox 26.

While the neck portion 107 of the lower primary air conduit 104 has beendescribed as being generally a half cylinder shape with the curvedportions (e.g., rear face 107 a) directed toward the center of thefirebox 26 and a box-shaped base portion 105 which extends toward therear wall 30 of the firebox 26, it will be understood that the lowerprimary air conduit 104 may have any suitable sizes, shapes, orconfigurations. For example, the neck portion 107 of the lower primaryair conduit 104 may be cylindrical, rectangular, conical, triangular, orany other suitable shape, and the base portion 105 may be cylindrical,half cylindrical, conical, triangular, funnel shaped, or any othersuitable shape.

In one embodiment, as best shown in FIGS. 21A-21C, the lower primary airconduit 104 has three conduit apertures 108 (a first conduit aperture108 a, a second conduit aperture 108 b, and a third conduit aperture 108c) disposed in the curved rear face 107 a of the neck portion 107 of thelower primary air conduit 104. The conduit apertures 108 a, 108 b, 108c, may be disposed in the neck portion 107 to provide flows of air atdifferent directions into the firebox 26. In some embodiments, the firstconduit aperture 108 a is disposed along a curved or angled portion ofthe rear face 107 a of the neck portion 107 and directed toward the leftside and/or rear wall 30, 32 of the firebox 26, the second conduitaperture 108 b is disposed in a central portion of the rear face 107 aof the neck portion 107 and directed substantially toward the rear wall30 of the firebox 26, and the third conduit aperture 108 c is disposedalong a curved or angled portion of the rear face 107 a of the neckportion 107 and directed toward the right side and/or rear walls 30, 34of the firebox 26. However, the neck portion 107 may have any suitablenumber and/or configuration of conduit apertures 108. For example, theneck portion 107 may have one, two, or four or more conduit apertures108 disposed in any suitable configuration to deliver primary air to thefirebox 26, such as in different directions. Further the aperture(s) maybe provided in a variety of shapes, including, for example, circular (asshown), elongated horizontal slot-shaped, or elongated verticalslot-shaped apertures.

In the illustrated embodiment, the second conduit aperture 108 b isdisposed below (e.g., closer to the floor 38 of the firebox 26) thefirst and third conduit apertures 108 a, 108 c. However, the conduitapertures 108 may have any suitable configuration. For example, allconduit apertures 108 may be disposed at substantially the same height,the first and third conduit apertures 108 a, 108 c may be disposed belowthe second conduit aperture 108 b, one of the first and third conduitapertures 108 a, 108 c may be disposed below the second conduit aperture108 b and the other of the first and third conduit apertures 108 a, 108c may be disposed above the second conduit aperture 108 b, or any othersuitable configuration.

The lower intake 106 may be sized, shaped, or otherwise configured tosupply the desired amount of primary air into and through the lowerprimary air conduit 104. For example, the lower intake 106 may besubstantially half-circular and have a diameter between about 0.25inches and about 0.50 inches, such as between about 0.30 inches andabout 0.40 inches, such as about 0.344 inches. However, the lower intake106 may have any suitable size, shape, or configuration. For example,the lower intake 106 may be triangular, rectangular, circular,elliptical, or any other suitable shape.

The conduit apertures 108 may be sized, shaped, or otherwise configuredsuch that primary air is fed into the firebox 26 from the conduitapertures 108 in the desired amount for primary combustion. The firstand third conduit apertures 108 a, 108 c may be substantially circularand have any suitable diameter. For example, the first and third conduitapertures 108 a, 108 c may be substantially circular and each have adiameter between about 0.20 inches and about 0.50 inches, such asbetween about 0.25 inches and about 0.35 inches, such as about 0.3125inches. The second conduit aperture 108 b may be substantially circularand have any suitable diameter. For example, the second conduit aperture108 b may be substantially circular and have a diameter between about0.15 inches and about 0.40 inches, such as between about 0.20 inches andabout 0.30 inches, such as about 0.25 inches. However, the conduitapertures 108 may have any suitable size, shape, or configuration. Forexample, the conduit apertures 108 may be triangular, rectangular,elliptical, or any other suitable shape.

The conduit apertures 108 may be positioned, oriented, or otherwiseconfigured such that primary air is fed into the firebox 26 in thedesired direction(s) or orientation(s). For example, the conduitapertures 108 may be oriented or otherwise configured to increase heatoutput of the stove 10, increase the heating efficiency of the stove 10,and/or to reduce particulate emissions from combustion in the stove 10.The first and third conduit apertures 108 a, 108 c may be disposed inthe rear face 107 a of the neck portion 107 and angled or oriented todirect primary air into the firebox 26 at an angle between the rear wall30 and the left and right side walls 32, 34, respectively, as desiredfor primary combustion. The first and third conduit apertures 108 a, 108c may each be oriented or otherwise configured at an angle with respectto a vertical plane extending rearward (e.g., toward the rear wall 30)from a medial portion of the lower primary air conduit 104, such as toat least partially direct flows of primary air toward the left and rightside walls 32, 34. For example, the first and third conduit apertures108 a, 108 c may be positioned in the rear face 107 a of the neckportion 107 at an angle with respect to the vertical plane extendingrearwardly from the medial portion of the rear face 107 a between about30° and about 60° toward the left or right side wall 32, 34,respectively, such as between about 40° and about 50°, such as about45°. The first and third conduit apertures 108 a, 108 c may be angledoppositely with respect to the vertical plane extending rearwardly fromthe medial portion of the rear face 107 a. The second conduit aperture108 b may be disposed in the rear face 107 a of the neck portion 107 andoriented or otherwise configured to direct a flow of primary airsubstantially rearward from the lower primary air conduit 104. However,the second conduit aperture 108 b may have any suitable orientation. Forexample, the second conduit aperture 108 b may be angled between about0° and about 20° toward either the left or right side wall 32, 34, suchas between about 0° and about 10° toward either the left or right sidewall 32, 34.

The conduit apertures 108 disposed in the rear face 107 a of the neckportion 107 may also be positioned in the lower primary air conduit 104relative to the floor 38 of the firebox 26 in any suitable manner toprovide the desired flow of primary air for primary combustion in thefirebox 26. For example, the conduit apertures 108 may be positioned toincrease heat output of the stove 10, increase the heating efficiency ofthe stove 10, and/or to reduce particulate emissions from combustion inthe stove 10. The second conduit aperture 108 b may be positioned at anysuitable location in the neck portion 107 to direct primary air at thedesired height or location into the firebox 26. For example, the secondconduit aperture 108 b may be disposed in the rear face 107 a of theneck portion 107 and elevated between about 0 inches and about 2.0inches above the floor 38 of the firebox 26, such as between about 0.5inches and 1.5 inches above the floor 38 of the firebox 26, such asabout 1 inch above the floor 38 of the firebox 26. The first and thirdconduit apertures 108 a, 108 c may also be disposed in the rear face 107a of the neck portion 107 and positioned at any suitable location in theneck portion 107 to direct primary air at the desired height or locationinto the firebox 26. For example, the first and third conduit apertures108 a, 108 c may be elevated between about 0.4 inches and about 2.6inches above the floor 38 of the firebox 26, such as between about 0.8inches and about 2.0 inches above the floor 38 of the firebox 26, suchas about 1.4 inches above the floor 38 of the firebox 26.

The lower primary air conduit 104 may provide a third flow of air or asecond flow of primary air into the firebox 26 for a primary combustionof a fuel placed in the firebox 26. Air may flow into the housing 12through the rear air opening 74 into the lower portion 25 of the housing12. The air may then flow from the lower portion 25 of the housing 12into the base portion 105 of the lower primary air conduit 104 throughthe lower intake 106, into the neck portion 107 of the lower primary airconduit 104, and then into the firebox 26 through the one or moreconduit apertures 108 of the lower primary air conduit 104, such asconduit apertures 108 disposed in the neck portion 107 of the lowerprimary air conduit 104.

In the illustrated embodiment, as best shown in FIGS. 21A-21B, the lowerprimary air conduit 104 includes fourth and fifth conduit apertures 108d, 108 e disposed in the base portion 105 of the lower primary airconduit 104. The fourth and fifth conduit apertures 108 d, 108 e may bepositioned in the base portion 105 in any suitable manner to provide thedesired flow of primary air for primary combustion in the firebox 26.For example, the fourth and fifth conduit apertures 108 d, 108 e may bepositioned to increase heat output of the stove 10, increase the heatingefficiency of the stove 10, and/or to reduce particulate emissions fromcombustion in the stove 10. The fourth and fifth conduit apertures 108d, 108 e may be sized and shaped to direct a second flow of primary airupwardly from the base portion 105 and toward a central portion of thefirebox 26 for a primary combustion of a fuel. However, in otherembodiments, the lower primary air conduit 104 may not have fourth andfifth conduit apertures 108 d, 108 e. For example, the base portion 105of the lower primary air conduit 104 may be solid without fourth orfifth conduit apertures 108 d, 108 e in the lower portion.

As shown in FIGS. 1-6 , the stove 10 may include a flue 112 in the top22 of the housing 12 and in communication with the firebox 26. The flue112 may be configured such that exhaust or emissions generated by thecombustion of fuel in the firebox 26 may flow out of or exit the firebox26 and the stove 10. The flue 112 may include a collar 114 disposedaround the flue 112 which extends upwardly and may be connected to achimney, as detailed below.

Turning now to FIGS. 26-29 , the stove 10 may be connected to a chimney116 to permit exhaust or emissions generated by the combustion of fuelin the firebox 26 to flow out of a structure or location in which thestove 10 is located.

As shown in FIGS. 26-29 , the stove 10 may include one or more chimneyconnectors 118 configured to connect the stove 10 to the chimney 116 andallow exhaust or emissions generated by combustion of fuel in thefirebox 26 to flow out of or exit the chimney 116. The chimneyconnectors 118 may be connected or otherwise configured to vent air outfrom inside the stove 10 to a location outside the house or structure inwhich the stove 10 is located. The chimney connectors 118 may besubstantially straight, bent, or curved to direct the stove 10 exhaustas desired. The chimney connectors 118 may be connected to the housing12, other chimney connectors 118, and/or the chimney 116. For example,as shown in FIG. 26 , one or more chimney connectors 118 may be attachedto the collar 114 of the flue 112 such that the exhaust of the stove 10may vent from the flue 112 to the chimney 116, such as with the use of achimney collar 120 and a thimble 122. The thimble 122 may provide an airflow entrance into the chimney 116 and the chimney collar 120 mayprovide an airtight seal around the connections of two chimneyconnectors 118, between one of the chimney connectors 118 and thethimble 122, or between one of the chimney connectors 118 and a portionof the structure. Additionally, as shown in FIG. 27 , one or morechimney connectors 118 may be attached to the stove 10 such that theexhaust of the stove 10 may vent through a non-combustible structurewall, such as into an external chimney 124 with a chimney cap 126 meantto provide a vented cover for the external chimney 124 (or chimney 116).Further, as shown in FIGS. 28 and 29 , the chimney connectors 118 may beattached to the stove 10 in a substantially vertical configuration suchthat the exhaust of the stove 10 may vent through a roof of a structure,such as into an external chimney 124 with a chimney cap 126

As shown in FIGS. 1-8, 13-14, and 24 the stove 10 may include a shroud109 configured to provide heat from combustion in the firebox 26 of thestove 10 into the room or area in which the stove 10 is located. Theshroud 109 may extend around the rear side 16 of the housing 12 andaround at least a part of the left and right sides 18, 20 of the housing12. In one embodiment, the shroud 109 is integral with the rear side 16of the housing 12 and at least parts of the left and right sides 18, 20of the housing 12. The shroud 109 may comprise a singular piece or maycomprise multiple components. The shroud 109 may be configured such thatair within the shroud 109 may be heated by combustion in the firebox 26.The shroud 109 may include one or more side vents 111 disposed at theend of the shroud 109 on the left and right sides 18, 20 of the housing12 which may allow heated air from within the shroud 109 to flow out ofthe shroud 109 and thereby provide heat to the area surrounding thestove 10.

The shroud 109 may also include a rear vent 113 configured to take in,pull in, or receive air from outside the stove 10. The rear vent 113 mayhave any suitable size, shape, or configuration to pull in or receiveoutside air into the shroud 109 as desired. The rear vent 113 may besubstantially rectangular and disposed in a rear portion of the shroud109 which may correspond to the rear side 16 of the housing 12. The rearvent 113 may be disposed in the rear portion of the shroud 109 and me bedisposed in the lower middle portion of the shroud 109 corresponding tothe rear side 16 of the housing 12. The rear vent 113 may be an openingor may include one or more baffles which may direct the flow of airthrough the shroud 109 as desired. However, the rear vent 113 may haveany suitable size, shape, position, or configuration. For example, therear vent 113 may be circular, triangular, or any other suitable shapeand may be disposed in any suitable location in the shroud 109.Additionally, the shroud 109 may include one or more interior baffleswhich may direct air within the shroud 109 as desired, such as from therear vent 113 to the side vents 111.

As shown in FIGS. 14 and 25 , the stove 10 may also include a fan orblower 110 configured to supply air from outside the stove 10 into andthrough the shroud 109 to supply a desired amount of heat to the areasurrounding the stove 10. The blower 110 may provide air from outsidethe stove 10 into the shroud 109 to be heated and then expelled throughthe side vents 111. The blower 110 may be disposed on the shroud 109,such as in the rear vent 113. The blower 110 and rear vent 113 may beconfigured such that the blower 110 may be attached to the shroud 109,such as with one or more fasteners, and the blower 110 may substantiallyfill the rear vent 113 when attached to the shroud 109.

The blower 110 may include a motorized fan to provide an increased flowof air into the shroud 109 from outside the stove 10. For example, theblower may be motorized or powered to provide air into the shroud 109.The blower 110 may have a variety of settings or be configured toprovide airflow at any desired amount to provide the desired amount ofheat or air output out of side vents 111 of the shroud 109. For example,the blower 110 may have a low setting for low airflow, a medium settingfor medium airflow, and a high setting for high airflow to provide thedesired output out of the side vents 111 of the shroud 109.

The stove 10, including any combination of the component parts describedabove, may be configured to provide a suitable or desired heat outputrange, particulate emissions rate, and/or efficiency. The stove 10 mayhave an increased heat output range. For example, the stove 10 may beconfigured to have a heat output range between about 10,000 BTU/hour andabout 90,000 BTU/hour, such as between about 30,000 BTU/hour and about70,000 BTU/hour, such as between about 40,000 BTU/hour and about 50,000BTU/hour. The stove 10 may also be configured to have an improvedparticulate emissions rate and/or improved weighted particulateemissions rate, wherein the weighted particulate emissions rate is aweighted average of the particulate emissions rates of the stove 10 inhigh, medium, and low burn modes. For example, the stove 10 may have aparticulate emissions rate between about 0.5 grams/hour and about 2.5grams/hour, such as between about 0.75 grams/hour and about 1.5grams/hour, such as about 0.99 grams/hour. The stove 10 may also have aweighted particulate emissions rate between about 0.5 grams/hour andabout 2.5 grams/hour, such as between about 0.75 grams/hour and about1.5 grams/hour, such as about 0.99 grams/hour. The stove 10 may furtherbe configured to have an increased efficiency or higher heating value(“HHV”). For example, the stove 10 may have an efficiency between about60% HHV and about 85% HHV, such as between 65% HHV and 70% HHV, such asabout 70% HHV or about 75% HHV

FIG. 30 shows steps according to an exemplary method 200 for providingheat from a wood burning stove. It will be appreciated that theillustrated method and associated steps may be performed in a differentorder, with illustrated steps omitted, with additional steps added, orwith a combination of reordered, combined, omitted, or additional steps.

At step 202, a primary damper (e.g., primary damper 82) is moved to theopen position. At step 204, kindling and fuel are provided into thefirebox (e.g., firebox 26). The fuel may be wood, such as cord wood,which is combustible in the firebox and the kindling may include smallerpieces of fuel, such as wood, paper, or other suitable material. At step206, the kindling and/or fuel in the firebox may be ignited, such as bya match, lighter, torch, or other suitable igniter. At step 208, a firstprimary air flow is provided to the firebox from a first air flowchannel (e.g., first air flow channel 76) for primary combustion of thefuel and/or kindling in the firebox. At step 210, a secondary air flowis provided to the firebox from one or more secondary air tubes (e.g.,secondary air tubes 96) for secondary combustion of the fuel and/orkindling in the firebox. At step 212, a second primary air flow isprovided to the firebox from a lower primary air conduit (e.g., lowerprimary air conduit 104). The second primary air flow may be provided tothe firebox through one or more conduit apertures in the lower primaryair conduit, such as conduit apertures in a neck portion of the lowerprimary air conduit and/or conduit apertures in a base portion of thelower primary air conduit. At step 214, air from outside the stove isprovided into a shroud of the stove to be heated. In some embodiments,the air may be provided into the shroud by a blower or fan. At step 216,a door (e.g., door 50) to the stove is partially closed which may stillpermit some air flow into the firebox from outside the stove. At step218, the door is closed fully and may be secured to the housing of thestove, such as by a lever (e.g., by rotation of lever 54).Alternatively, step 216 may be omitted and the door may be closedwithout partially closing the door first. At step 220, the primarydamper is moved to the desired position for combustion in the firebox,such as the fully open position for a desired high burn setting, apartially open position for a medium burn setting, or a closed positionfor a low burn setting. At step 222, heated air within the shroud ismoved out of one or more side vents in the shroud to provided heated airto the area surrounding the stove. In some embodiments, the heated airmay be moved through the shroud by a blower or fan.

While various inventive aspects, concepts and features of thedisclosures may be described and illustrated herein as embodied incombination in the exemplary embodiments, these various aspects,concepts, and features may be used in many alternative embodiments,either individually or in various combinations and sub-combinationsthereof. Unless expressly excluded herein all such combinations andsub-combinations are intended to be within the scope of the presentapplication. Still further, while various alternative embodiments as tothe various aspects, concepts, and features of the disclosures—such asalternative materials, structures, configurations, methods, devices, andcomponents, alternatives as to form, fit, and function, and so on—may bedescribed herein, such descriptions are not intended to be a complete orexhaustive list of available alternative embodiments, whether presentlyknown or later developed. Those skilled in the art may readily adopt oneor more of the inventive aspects, concepts, or features into additionalembodiments and uses within the scope of the present application even ifsuch embodiments are not expressly disclosed herein.

Additionally, even though some features, concepts, or aspects of thedisclosures may be described herein as being a preferred arrangement ormethod, such description is not intended to suggest that such feature isrequired or necessary unless expressly so stated. Still further,exemplary or representative values and ranges may be included to assistin understanding the present application, however, such values andranges are not to be construed in a limiting sense and are intended tobe critical values or ranges only if so expressly stated.

Parameters identified as “approximate” or “about” a specified value areintended to include both the specified value and values within 5% orwithin 10% of the specified value, unless expressly stated otherwise.Further, it is to be understood that the drawings accompanying thepresent disclosure may, but need not, be to scale, and therefore may beunderstood as teaching various ratios and proportions evident in thedrawings.

Moreover, while various aspects, features and concepts may be expresslyidentified herein as being inventive or forming part of a disclosure,such identification is not intended to be exclusive, but rather theremay be inventive aspects, concepts, and features that are fullydescribed herein without being expressly identified as such or as partof a specific disclosure, the disclosures instead being set forth in theappended claims. Descriptions of exemplary methods or processes are notlimited to inclusion of all steps as being required in all cases, nor isthe order that the steps are presented to be construed as required ornecessary unless expressly so stated. The words used in the claims havetheir full ordinary meanings and are not limited in any way by thedescription of the embodiments in the specification.

1. A lower primary air conduit for use in a wood burning stove, thelower primary air conduit comprising: a base portion and a neck portiondisposed above the base portion; an intake disposed in a bottom of thebase portion; and a plurality of conduit apertures disposed in a rearface of the neck portion, with the base portion extending rearward ofthe rear face of the neck portion; wherein the plurality of conduitapertures are configured to direct a flow of primary air into a fireboxof the wood burning stove.
 2. The lower primary air conduit according toclaim 1, wherein the plurality of conduit apertures are oriented indifferent directions.
 3. The lower primary air conduit according toclaim 1, wherein the plurality of conduit apertures comprises a middleconduit aperture that is oriented to direct the flow of primary airrearwardly.
 4. The lower primary air conduit according to claim 1,wherein the plurality of conduit apertures comprises at least one sideconduit aperture that is oriented at a 45° angle away from the middleconduit aperture.
 5. The lower primary air conduit according to claim 1,wherein the lower primary air conduit includes three conduit apertures.6. The lower primary air conduit according to claim 1, wherein the neckportion includes a planar front face opposite the rear face.
 7. A woodburning stove comprising: a housing; a firebox enclosed by the housing;a primary air flow channel configured to provide a first flow of primaryair into the firebox; a secondary air flow channel configured to providesecondary air into the firebox; and a lower primary air conduitconfigured to provide a second flow of primary air into the firebox;wherein a portion of the secondary air flow channel is disposed abovethe primary air flow channel and the lower primary air conduit isdisposed below the primary air flow channel.
 8. The wood burning stoveaccording to claim 7, further comprising at least one secondary air tubedisposed in the secondary air flow channel.
 9. The wood burning stoveaccording to claim 8, wherein each of the at least one secondary airtube has a plurality of secondary air apertures.
 10. The wood burningstove according to claim 7, where the lower primary air conduit has aplurality of conduit apertures.
 11. The wood burning stove according toclaim 10, wherein the conduit apertures are oriented in differentdirections.
 12. The wood burning stove according to claim 7, wherein thestove has a weighted particulate emissions rate less than 1.0 grams perhour.
 13. The wood burning stove according to claim 7, wherein the lowerprimary air conduit comprises: a base portion and a neck portiondisposed above the base portion; an intake disposed in a bottom of thebase portion; and a plurality of conduit apertures disposed in a rearface of the neck portion; wherein the plurality of conduit apertures areconfigured to direct the second flow of primary air rearwardly into thefirebox.
 14. A method for providing heat from a wood burning stove, themethod comprising the steps: providing fuel in a firebox of the woodburning stove; igniting the fuel in the firebox; providing a firstprimary air flow into the firebox from a first air flow channel;providing a secondary air flow into the firebox from at least onesecondary air tube; providing a second primary air flow into the fireboxfrom a lower primary air conduit; providing a flow of air into a shroudof the stove; and moving heated air out of side vents of the shroud. 15.The method for providing heat from a wood burning stove according toclaim 14, further including the step of moving a primary damper to oneof a closed position, a partially open position, and an open position.16. The method for providing heat from a wood burning stove according toclaim 14, wherein the second primary air flow into the firebox isprovided from a plurality of conduit apertures in the lower primary airconduit.
 17. The method for providing heat from a wood burning stoveaccording to claim 16, wherein the plurality of conduit apertures in thelower primary air conduit are oriented in different directions.
 18. Themethod for providing heat from a wood burning stove according to claim14, wherein the wood burning stove comprises three secondary air tubeswith a plurality of apertures.
 19. The method for providing heat from awood burning stove according to claim 14, wherein a weighted particulateemissions rate from the wood burning stove is less than 1.0 gram perhour.
 20. The method for providing heat form a wood burning stoveaccording to claim 14, wherein the flow of air into the shroud isprovided from a blower.